Bash associative arrays and dynamically assign variables

Question

I faced with a very strange behavior.

#!/bin/bash

declare -A array_first=(
    [name]="Array 1"
    [message]="Hi there"
)

declare -A array_second=(
    [name]="Array 2"
    [message]="Bye!"
)

arrays=(array_first array_second)

for arr in ${!arrays[*]}
do
    val=${arrays[$arr]}
    val=${!val}
    echo ${val[name]} # Why this string is empty?
done

echo "${array_first[name]}"
echo "${array_first[message]}"

echo "${array_second[name]}"
echo "${array_second[message]}"

I need the value of an associative array, and displays an empty string. What am I doing wrong?

What are you trying to accomplish with the ${!val}?

Josh from Qaribou
– Josh from Qaribou

2014-05-18 22:23:59 +00:00
Commented May 18, 2014 at 22:23 — Josh from Qaribou
– Josh from Qaribou, Commented May 18, 2014 at 22:23

choroba · Accepted Answer · 2014-05-18 22:31:16Z

2

When combining ${!...} with arrays, you have to specify the index or key in the string you evaluate with !:

for arr in ${!arrays[*]}
do
    val=${arrays[$arr]}
    ex="$val[name]"
    echo ${!ex} # No longer empty.
done

answered May 18, 2014 at 22:31

choroba

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